I washed it like they say you shouldn't...by submerging it.I'm curious how you determined it was time to replace it. I don't recall seeing anything from Helite other than send it back for inspection after six deployments or when there is visible damage. Maybe Hit-Air is different?
I think I purchased that initial vest back in 2010 or so. The replacement was in 2022. So it lasted me at least 12 years.
Chris